unknown problem

i brought a 1995 aurora i changed the plugs wires pcv valve fuel filter air filter and i still have a problem. my check engine light would come on and when it does my car drive different when i get to 40 mph my rpm would drop, rise and drop until i get to 70 mph then it drive fine and also when my check engine light on my car shift rough but when the engine light off the car run fine and shift smooth can someone help me out??

you bought DTC 56 most likely.... check DTC's at some place who can read 95 aurora's. i don't recommend to drive it until you fix it. it's about 1500$ job in usa if it's 56/ISS malfunction.

also - coils...

Sounds like a tranny problem in second gear. How's your tranny fluid? See if there's metal filings in the fluid. If all is OK, could be a sylenoid, or the torque converter.

NO METAL IN THE TRANNY FLUID IT STRANGE BECAUSE MY CHECK ENGINE LIGHT WOULD COME ON THEN IF I PRESS THE PEDAL A LITTLE IT GOES OFF BUT YOU SAID IT COULD BE THE sylenoid, or the torque converter.??? I DONT KNOW ALOT ABOUT CARS??